Preeclampsia is the development of hypertension with proteinuria or edema in pregnant women between the twentieth week of pregnancy and the end of the first week following delivery without apparent cause. Preeclampsia develops in roughly 5% of pregnant women, typically in women with a prior history of hypertension or vascular disease. If left untreated, preeclampsia can often rapidly progress to eclampsia which is fatal if untreated and which occurs in about 1 out of every 200 women who develop preeclampsia.
Mild preeclampsia is typically treated with bed rest. If the condition persists or develops into eclampsia, the usual treatment is the immediate induction of labor and delivery of the fetus.
In patients at high risk for the development of preeclampsia, low-dose aspirin therapy has also been tried as a preventative measure, but the data on the results are mixed. U.S. Pat. No. 5,015,648 discloses the use of (1R-(1.alpha.(Z),2.beta.,3.beta.,5.alpha.))-(+)-7-(5-((1,1'-biphenyl)-4 -yl)methoxy-3-hydroxy-2-( 1-piperidinyl)cyclopentyl)-4-heptenoic acid or one of its physiologically acceptable salts for the therapy or prophylaxis of conditions associated with vasoconstriction and/or platelet aggregation in the uteroplacental circulation and/or excessive synthesis of thromboxane A.sub.2 in the pregnant female subject.